Research on a New Reliability Assessment Method for Zero-failure Data

In order to analyze the reliability of the high reliability electronic and electromechanical products, a modified unilateral confidence limit analysis method under the condition of zero-failure data is proposed, which introduces the failure information into the confidence limit analysis. The failure rate of the product is estimated by Bayes parameter, and the data of the product with different truncation times are obtained. The time coefficients are equivalently replaced according to the proposed method, and then the reliability of product and the mean time between failures can be known. Based on the zero-failure data of a robot stepping motor, the calculated results of the proposed method is compared with those of the other unilateral confidence limit methods. The results show that, under the confidence level of 0.99, the mean time between failures of the product is 37 080 h, which is less than the calculated result of other confidence limit methods. The reliability of the product is estimated to be 0.973 by using the proposed new method when the mission time reaches 1 000 h. The example analysis proves the effectiveness of the new method in the reliability evaluation of zero-failure data products, and can prevent the product reliability and the mean time between failures estimation from occurrence.